Treating corrugated surfaced sheets



Aprll 16, 1963 A. N. OOSTLAND TREATING CORRUGATED SURFACED SHEETS INVENTOR. ALFRED H. OOSTLAND Filed April 20, 1961 3,085,368 Patented Apr. 16, 1963 ire - 3,035,368 TREATING CQRRUGATED SACED SHEETS Alfred N. Oostland, Kingsport, Team, assignor to Compagnie do Saint-Gobain, Neuilly-sur-=Seine, France Filed Apr. 20, 1961, Ser. No. 104,424 Claims priority, application France Apr. 29, 1960 18 Claims. (Cl. 51-14) The present invention relates to an apparatus for and a method of treating corrugated surfaced sheets. Among the sheets which may be treated in accordance with the invention are sheets of glass having at least one broad face thereof provided with parallel ribs and grooves. Treatment of such sheet in accordance with one embodiment of the invention involves the frosting of spaced parallel bands of the corrugated face of the sheet as by sand blasting.

Such frosting of spaced bands of the corrugated face of a glass sheet is conventionally carried out by sand blasting such bands while the remainder of the sheet exposed to the action of the sand blast is protected as by means of strips of paper which have been pasted upon those areas, for example, alternate channels or corrugations, which it is desired not to frost. Much time is consumed in mounting such paper strips accurately upon the sheet of glass. If the paper strips are not mounted accurately the alternating polished and frosted strips on the surface of the glass after it has been sand blasted will not be par allel, and therefore presents defects in appearance. In addition, with such method it is necessary to remove the strips of paper from the glass surface after the sand blasting operation. This must be done either by subjecting the strips to the action of steam or very hot water in order to dissolve the paste or glue employed in mounting the strips on the glass. Following this, the paper strips are removed by brushing, the surface of the glass then being cleaned, rinsed, and then dried.

It has been proposed to use masking tape provided with pressure sensitive adhesive instead of the paper strips which must be secured to the glass by glue or paste. Such masking tape decreases the amount of labor necessary, particularly since it may be removed from the glass by being merely pulled therefrom and since it does not leave any deposit on the glass. However, such masking tape requires the same careful and precise mounting of it in place on the surface of the glass sheet to be treated. Also, the cost of such masking tape is relatively high, and such tape becomes worn out after two or three uses of it be cause of its perforation by the sand blast.

, The present invention has among its objects the elimination of the difiiculties above outlined which are attendant upon the use of either paste or glue-secured paper masking strips or masking tape provided with pressuresensitive adhesive.

In accordance with a preferred embodiment of the invention, masks are placed over the surface of the glass sheet between the sheet and the nozzle of the sand blast mechanism. These masks are formed of bars of magnetic material or -a substantial portion of these masks is made of such material and they are subjected to the action of a magnetic field which maintains them over the zones of the glass sheet which are to be protected and prevents the displacement of the masks during the movement of the glass sheet.

Besides eliminating the above outlined difliculties accompanying the use of paper strips or of masking tape, the invention has other advantages. The magnetic masking bars are readily and quickly placed in the desired position upon the corrugated glass sheet to be treated. Thus a treating station provided with masking means in accordance with the present invention may be disposed in series with the rolling machines for forming the sheet of glass. Thus the frosting of the glass may take place as one of a series of steps performed upon the glass during its continuous fabrication.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a somewhat schematic view in vertical section through a first embodiment of sheet treating apparatile in accordance with the invention;

FIG. 2 is a view in perspective of the sheet-treating portion of the apparatus shown in FIG. 1;

FIG. 3 is a fragmentary view in vertical section through a first form of corrugated glass sheet and a number of masking devices disposed thereon in accordance with the invention;

FIG. 4 is a view similar to FIG. 3 but showing another embodiment of corrugated glass sheet having a plurality of masking devices in accordance with a second embodiment of the invention mounted thereon; and

FIG. 5 is a somewhat schematic view in vertical section through a second embodiment of sheet treating apparatus in accordance with the invention.

In the drawings, the embodiment of glass sheet shown being treated is in both instances corrugated on one side only, the other side of the sheet being flat. It is to be understood, however, that the invention may be applied to the treatment of sheets in which both sides are corrugated. For example, the devices of FIGS. 1 and 5 may be disposed to act upon the double-corrugated sheet in sequence.

In FIG. 1 a sheet of glass 1 corrugated longitudinally on its upper face is shown issuing from a set of glassforming rolls 17 and 18. The glass sheet continues its travel to the right upon conveyor rollers of which one is shown at 3, and enters a sand blasting station which is shown schematically at the right in FIG. 1 and in more detail in FIG. 2. The glass sheet 1, which is shown in section in FIG. 4, has a plurality of longitudinally directed similar curved channels 2 on its upper face. It is to be understood that, with a suitable change in contour of the glass-forming rolls such as that shown at 17 in FIG. 1, the contour of the corrugations may be changed as desired. For example, the glass sheet may have the configuration of that designated 1a in FIG. 3, wherein the upper face has a plurality of similar longitudinally directed shallow curved projections 16.

The sand blasting station shown in FIG. 1 includes a laterally extending chamber 4, the sheet-entering edge of the chamber being provided with a laterally extending seal 5, and the sheet-discharging edge of the chamber having a laterally extending seal 6, both such seals sub-. stantially preventing the escape of abrasive grains from the chamber. A laterally extended nozzle 7 has its lower discharge end connected to the chamber, air being admitted tothe nozzle from the atmosphere through an elongated slot 9 above which is disposed an abrasive grain-containing trough 8. Abrasive grain is discharged through a slot in the bottom of trough 8 and thence into the nozzle 7.

The sand blasting device shown operates on the vacuum principle, the mixture of air and sand being drawn by chamber 4 subjected to sub-atmospheric pressure, so that as a result of the partial vacuum in the chamber abrasive grains entrained in the air traveling at high speed through nozzle 7 are projected upon the unmasked portions of in detail in FIG. 4. Masks 10 are in the form of bars made of magnetic material such as steel, the lower surfaces of the bars accurately fitting or mating with the surface of the zones 2 which are to be protected. In the apparatus shown there is disposed a device establishing a magnetic circuit beneath the sheet 1, the circuitbeing so disposed as to pass through the active treating zone of the sand blasting apparatus. Specifically, the magnetic circuit-forming means includes opposite pole pieces 11 and 11a between which is disposed a plurality of wound magnet coils 12. The upper ends of the pole pieces 11 and 11a are bent inwardly, then upwardly, and then again inwardly toward each other, the last named portions of the polepieces being separated by a narrow transversely extending gap 13'. Such upper and centrally inner portions of the pole pieces lie close to or actually engage the lower surface of the 811661221.

It will be apparent that the magnetic flux created by the coils 12 crosses the gap 13- and is closed through the masks 10. The masks are thus submitted to the action of the magnetic lines of force which are directed parallel to the direction of travel of the glass sheet and thus lie parallel to the corrugations 2.. Thus the natural tendency of the masks to lie in their respective channels is strongly augmented by the magnetic attraction to which they are subjected and by the preferential orientation to which they are subjected by the lines of force of the magnetic field.

The masks 10 may readily be put in place upon the sheet 1 by being placed in the respective channels at the leading end of the sheet before such end reaches the sand blasting station; When such a sheet of glass, with the masks lying thereon, reaches the sand blasting station, the masks are capturedby the magnetic field and are seated strongly in the positions shown in FIGS. 1 and 2 as the glass sheets'nrove under the masks during the sand blasting 'operation. Because of their accurate interfitting with the channels on the glass which it is not desired to frost, only the portions of the upper face of the glass sheet which lie between the masks are frosted.

In FIG. 3 there is shown an alternative mask 10a which may be employed in connection with a glass sheet la having a corrugated surface in the form of a plurality of longitudinally extending similar shallow curved ribs or projections 16. The masks lint-shown are of such width as to span one of the curved zones 16, the loweredges of the mask having guiding engagement with the troughlike zones of intersection between successive ribs 16. It is to be understood that the mask 10a, andalso the mask 10 of FIG. 4, may, in accordance with the product desired, be made of such width as to span a plurality of the convex zones 16 (FIG. 3) or a plurality of the concave zones 2 (FIG. 4).

The above-described embodiment of the apparatus treats (specifically sand blasts) the upper corrugated face of a glass sheet. It is sometimes of advantage, however, thus to treat the lower face of a glass sheet as, for example, when the sand blasting station is disposed in series with the glass rolling mechanism which has formed the corrugated face of the glass sheet. In such last described system the smooth polished face of the glass is not engaged. by conveying rolls which might injure the polish of such face. In FIG. 5 there is shown a second embodiment of sand blasting apparatus in accordance with the invention,- such apparatus treating the lower face of a sheet of glass :11) of which the lower face is longitudinally corrugated and the upper face is smooth.

In the apparatus of FIG. 5 the elements which are generally similar to those of FIGS. 1 and 2 are designated by the same reference characters with an added prime. In FIG. 5 the chamber 4 is disposed beneath the glass sheet 1b, the nozzle '7' is upwardly directed and the slit 9', after picking up abrasive grains from trough 8, introduces them into the lower end of nozzle 7. The magnetic field-producing device 12, which is similar to that of FIGS. 1 and 2, isdisposed above the sheet 1b in inverted position as regards the first described embodiment.

At the upper, sand blasting zone of chamber 4', there are disposed transversely extending rails 14, the left-hand rail, at the entering end of the apparatus, lying somewhat below the rail at the exit end of the apparatus. A plurality-of masks 15, which in their active portions may have sections similar to that of either of FIGS. 3 and 4, depending upon the contour of the corrugations, are mounted so that the right-hand ends of the masks are hinged to the right-hand rail 14. The disposition of the parts is such that when the electromagnetic means 12' is deenergized the masks 15- lie upon both rails 14 in the lower inoperative position thereof shown in dotted lines. When, however, the electromagnetic means 12 is enengized, the masks 15 are pulled strongly upwardly into the horizontal operative position shown in full lines, wherein each of the masks is guidingly engaged with its respective one or more corrugations.

It is to be understood that the invention is not limited to the sand blasting of sheets of glass. The apparatus and method of the invention may be used to advantage, for example, in the selective coloring of the corrugations. In such application of the invention there is employed one or more paint spray guns which direct a spray of paint or enamel upon the unmasked portions of the sheet material. Following such coating of the sheet it may be subjected to thermal treatment in order to dry the projected paint or enamel.

Although only a limited number of embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing specification, it is to be especially understood that various changes, such as in the relative dimensions of the parts, materials used,

and the like, as well as the suggested manner of use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention as will now be apparent to those skilled in the art.

What is claimed is:

1. An apparatus for treating spaced parallel bands of a sheet of materal having parallel corrugations on at least one broad face thereof, said apparatus having a station for treating the said parallel bands, and means for producing relative displacement between the sheet and the station in a direction parallel to the corrugations in said face of the sheet, the improved mechanism for masking at said station the bands of the sheet which are not to be treated which comprises a plurality of spaced parallel masks disposed on the said face of the sheet at the treat- =ing station, said masks being mounted with at least portions thereof guidingly engaging selected ones of the corrugations, the masks covering selected bands of the sheet at the treating station while leaving exposed the bands to be treated, at least a substantial portion of the masks being made of magnetic material, and means disposed on the other side of the sheet having magnetic attraction to the masks to retain the masks fixed with respect to the treating station as the sheet travels with respect to the station.

2. Apparatus as defined by claim 1, wherein the means disposed on the other side of the sheet is an electromagnet having opposed poles spaced by a gap extending transversely to the direction of the corrugations in said one face of the sheet, said'igap lying opposite said masks.

3. Apparatus as defined by claim 1, wherein the masks are in the form of magnetic bars having at least their longitudinal edges guidingly engaging longitudinal elements of selected ones of said corrugations.

4. Apparatus as defined by claim 3, wherein the corrugations on the said one face of the sheet are in the form of relatively broad depressed channels, and each of the bars has a width substantially equal to the width of its respective channel and a sheet-engaging face which accurately conforms to the contour of the broad surface of such channel.

5. Apparatus as defined by claim 1, wherein the corrugations on said one face of the sheet are in the form of relatively broad raised ribs, the side edges of adjacent ribs meeting at parallel grooves, and each of the masks is of such width and shape as to span across at least one rib and to have its edges guidingly engaged in spaced grooves on said one face of the sheet.

6. Apparatus as defined in claim 1, wherein the sheet is disposed horizontal, a corrugated face of the sheet is disposed uppermost, and the masks are mounted on the upper face of the sheet.

7. Apparatus as defined in claim 1, wherein the sheet is disposed horizontal, a corrugated face of the sheet is disposed lowermost, and the masks are mounted below the sheet so as to engage the lower face thereof.

8. Apparatus as defined in claim 7, comprising means to support the sheet in a horizontal plane for travel relative to the treating station, and means disposed beneath the sheet selectively to support the masks near but generally spaced from the lower face of the sheet, and wherein the means disposed on the other side of the sheet having magnetic attraction to the masks is selectively operative to raise the masks by such attraction into operative engagement with the sheet.

9. Apparatus as defined by claim 1, wherein the treating station includes means for treating the portions of the corrugated face of the sheet exposed between the masks by projection.

10. Apparatus as defined by claim 9, wherein the means for treating the said exposed portions of the corrugated face of the sheet projects particles of treating material against said exposed portions.

11. Apparatus as defined by claim 10, wherein the sheet is made of glass, and the means for treating the said exposed portions of the corrugated face of the sheet projects a blast of finely divided abrasive particles against such portions.

12. Apparatus as defined by claim 1, wherein the sheet travels and the treating station is stationary, and comprising sheet forming means disposed in advance of the treating station, the sheet traveling through the forming means and from the forming means to and through the treating station.

13. Apparatus as defined in claim 12, wherein the sheet is made of glass, the forming means comprises c-orrugating rolls, and the treating station includes means for sand blasting the portions of the corrugated face of the glass sheet exposed by the masks.

14. The method of treating spaced parallel bands of a sheet of material having parallel corrugations on at least one broad face thereof, which comprises disposing a plurality of separate unconnected spaced parallel magnetic masks aligned transversely of the corrugations on the said face of the sheet, laterally locating the masks by their engagement with selected surfaces of the corrugations, positioning the masks longitudinally by subjecting them to the action of a magnetic field in which the masks form a part of a magnetic circuit, moving the sheet longitudinally relative to the masks, and treating the portions of the sheet exposed between the masks.

15. The method of treating a sheet of material as defined by claim 14, wherein the sheet is non-magnetic, and the sheet travels and the masks remain fixed longitudinally.

16. The method of treating a sheet of material as defined by claim 15, wherein the sheet is made of glass, and the portions of the sheet exposed between the masks are treated by sand blasting.

17. The method of treating a sheet [of material as defined by claim 15, comprising forming the sheet at a zone in advance of the zone of its treatment at the masks, and conveying the sheet continuously through the forming zone and the treating zone.

18. The method of treating a sheet of material as defined by claim 17, wherein the sheet is made of glass, and the portions of the sheet exposed between the masks are treated by sand blasting.

References Cited in the file of this patent UNITED STATES PATENTS 2,235,288 Duggan Mar. 18, 1941 

1. AN APPARATUS FOR TREATING SPACED PARALLEL BANDS OF A SHEET OF MATERIAL HAVING PARALLEL CORRUGATIONS ON AT LEAST ONE BROAD FACE THEREOF, SAID APPARATUS HAVING A STATION FOR TREATING THE SAID PARALLEL BANDS, AND MEANS FOR PRODUCING RELATIVE DISPLACEMENT BETWEEN THE SHEET AND THE STATION IN A DIRECTION PARALLEL TO THE CORRUGATIONS IN SAID FACE OF THE SHEET, THE IMPROVED MECHANISM FOR MASKING AT SAID STATION THE BANDS OF THE SHEET WHICH ARE NOT TO BE TREATED WHICH COMPRISES A PLURALITY OF SPACED PARALLEL MASKS DISPOSED ON THE SAID FACE OF THE SHEET AT THE TREATING STATION, SAID MASKS BEING MOUNTED WITH AT LEAST PORTIONS THEREOF GUIDINGLY ENGAGING SELECTED ONES OF THE CORRUGATIONS, THE MASKS COVERING SELECTED BANDS OF THE SHEET 